Phospholipids, which are basic constituents of biomembranes, belong to lipids controlling basic life activities including protection of cellular tissues, transfer of information and controlling of the migration of substances.
Recently it has attracted scientific and industrial attention that vesicles or liposomes comprising a phospholipid capable of forming a bilayer membrane can include various functional substances. These vesicles are expected to be applicable to, for example, a drug delivery system (DDS) in the field of medicine and pharmacology.
We have studied the application of these highly functional lipids to the food industry and successfully developed a cooking oil showing no oil spattering and excellent release properties by using PA which is one of phospholipids (refer to JP-A-1-27431; the term "JP-A" as used herein means an "unexamined published Japanese patent application").
Examples of the industrial uses of PA include application of PA to foods for, e.g., improving dough properties in a baking process as described in JP-A-58-51853 (corresponding to U.S. Pat. No. 4,478,866), producing an emulsifier comprising PA and a zein complex as described in JP-A-62-204838; application of PA to drugs as described in JP-A-54-105222, JP-A-55-11582 (corresponding to Canadian Patent 1121829), JP-A-56-127308 and JP-A-60-255728; application of PA to cosmetics as described in JP-A-59-27809 (corresponding to U.S. Pat. No. 4,874,791); and application of PA to chemicals as described in JP-A-53-108503 and JP-A-60-243171. Thus the application of PA has been attempted in various fields.
However it is highly difficult to collect PA at a high purity, since PA per se is contained in a small amount in lecithin which is a side product obtained in the production of an oil. No method for the production of PA on an industrial scale has been established so far. Accordingly, the application range of PA is still restricted, compared with that of lecithin.